DE 10 2005 052 364 A1 discloses an electric motor, a spiral line for transporting a coolant being formed on the stator of said electric motor. The coolant lines are formed by a housing and a projection which runs in a spiral manner on the outer face of said housing parallel to the longitudinal axis of the electric motor, and also by a cup-like cover. The inflow and the outlet of the coolant lines are made in the cup-like cover, as a result of which it is necessary to establish connections to the coolant line axially on both sides.
One problem with this is that in the case of wheel hub motors, but also in the case of other electric motors, radial installation space is disadvantageously lost since a coolant line, for example in the form of a hose, has to be routed past the electric motor in the axial direction either from the inflow or from the outlet. On account of these dedicated feed lines, it would not be possible to utilize a relatively large annular installation space for the electric motor.
In addition, there are no alternatives for fitting a feed line of this kind either through the coils of the stator or closer to the rim because it would likewise not be possible to utilize a large annular installation space in either case, or a new problem would arise as a result of said feed line being routed through.